Sometimes living on a budget can make you do crazy things. Like going to Sam's Club and buying a 5 pound bag of fresh broccoli that goes bad before you use it all. Or stocking up on coconut milk because you just know the kids will love it and buying it in bulk on sale with coupons gets you each carton for $1.50. Then it sits in the pantry for 4 months and counting because the kids don't actually like the taste so you have to force them to add it in cereal which you only eat on the weekends so it lasts forever.
I hope that never happens to you.
But in all seriousness, when you live on a budget and see a good or great deal, the first instinct is to run out and immediately stock up. Especially if you have coupons. But if it's not something that is tried and proven a winner in your house, then you just wasted your money.
The point is, plan your meals and know what you use for toiletries. Buy what you need. If you see something is a great deal, first ask yourself if it's something you've used before. If the answer is no, don't load up until you've tried it.
Buying things that never get used is a complete waste of your budgeted dollars. And we can't have that!